When skin's metabolism or sebaceous gland function declines due, for example, to aging or stress, the skin becomes susceptible to external stimuli and develops various symptoms. For example, drying may increase the chance for feeling itchy. In addition, if the skin's fibrous component withers under exposure to ultraviolet rays, wrinkling and other symptoms will develop.
Skin aging such as wrinkle formation or reduced elasticity may occur due to various causes including fiber reduction, degeneration and regression of dermis matrices such as collagen and elastin.
The skin's dermis and epidermis are composed of cutaneous tissues comprising epidermal cells, fibroblast cells and extracellular matrices such as elastin and collagen that are outside those cells to support the skin structure. If the skin is young, the interactions of these cutaneous tissues keep homeostasis by which water retention, softness/flexibility, elasticity and other properties are ensured and apparently, the skin has resilience and glow and is maintained in a fresh condition. However, on account of external factors such as UV radiation, significant drying of the air, excessive skin washing and stress, as well as aging, elastin as a major constituent of the extracellular matrices will decompose or degenerate whereas collagen is not only produced in a smaller amount but also crosslinked to become less elastic. Consequently, the moisturizing function and elasticity of the skin decrease and the horny layer begins to shed off abnormally, whereupon the skin will lose its resilience and glow, eventually developing various symptoms including roughness, wrinkles, and dullness.
Plants of the family Rosaceae are quite diverse and among their varieties roses that are classified in the genus Rosa and which are utilized as flowers and ornamental plants are said to include as many as 3000 species, most of which are cultivars created by crossing and other conventional breeding methods. The hybrid cultivars are roughly classified into two types, Old Garden Rose and Modern Rose (Patent Document 1).
Pigments in roses have been investigated in detail. Take, for example, anthocyanin pigments which are known to include cyanidin 3,5-diglucoside, pelargonidin 3,5-diglucoside, cyaniding 3-glucoside, pelargonidin 3-glucoside, peonidin 3,5-diglucoside, and peonidin 3-glucoside. Also known are many carotenoid compounds that develop a yellow color. These pigments are simultaneously accumulated in flowers and ornamental plants which hence develop a red or yellow color.
“Madame Violet”, a mauve-hued rose variety, is known to contain rosacyanins as blue color pigment compounds (compounds I-III) (Patent Document 2). It is also known that the rose variety “APPLAUSE (registered trademark)” (or Suntory Blue Rose APPLAUSE (trademark)”) contains rosadelphins (compounds IV-VI) (Patent Document 3). These compounds have been characterized in terms of their structures, colors and various spectral data but their physiological activities and functionality are yet to be clarified.
Components in plants of the family Rosaceae have been reported to have various activity including antiallergic activity, skin lightening activity (melanin production suppressing activity or tyrosinase inhibiting activity), moisturizing activity, and antioxidizing activity. A patent document (Patent Document 4) discloses that extracts of Rosa hybrida and Rosa laevigata are effective as agents for suppressing mucopolysaccharide fragmentation. Another patent document (Patent Document 5) discloses that essences of plants of the family Rosaceae are effective as cosmetics for sensitive skin. Still another patent document (Patent Document 6) discloses that an extract of Rosa Centifolia is effective as a whitening agent for cutaneous application. To benefit from these effects of components derived from plants of the family Rosaceae, extracts and petals of roses called Old Garden Rose (of the genus Rosa) including Rosa Centifolia, Rosa Damascena, and Rosa Gallica have heretofore been used as agents for cutaneous application (e.g. cosmetics), bath salts, and flavors in foods or beverages. However, these rose varieties which have been used for non-ornamental purposes lack the aforementioned rosacyanins and rosadelphins.